openLink uses incorrect document position

[mickael-menu]

Result from CocInfo

## versions

vim version: NVIM v0.4.4
node version: v15.1.0
coc.nvim version: 0.0.80-6b4dd38af2
coc.nvim directory: /Users/mickael/.vim/plugged/coc.nvim
term: iTerm.app
platform: darwin

## Log of coc.nvim

2021-04-02T17:11:30.310 INFO (pid:84652) [services] - registered service "languageserver.zk"
2021-04-02T17:11:30.314 INFO (pid:84652) [services] - zk state change: stopped => starting
2021-04-02T17:11:30.317 INFO (pid:84652) [plugin] - coc.nvim 0.0.80-6b4dd38af2 initialized with node: v15.1.0 after 60ms
2021-04-02T17:11:30.321 INFO (pid:84652) [language-client-index] - Language server "languageserver.zk" started with 84657
2021-04-02T17:11:30.689 INFO (pid:84652) [services] - zk state change: starting => running
2021-04-02T17:11:30.693 INFO (pid:84652) [services] - service languageserver.zk started
2021-04-02T17:11:31.306 INFO (pid:84652) [attach] - receive notification: highlight []
2021-04-02T17:11:31.948 INFO (pid:84652) [attach] - receive notification: openLink []
2021-04-02T17:11:32.303 INFO (pid:84652) [attach] - receive notification: highlight []
2021-04-02T17:11:33.383 INFO (pid:84652) [attach] - receive notification: highlight []
2021-04-02T17:11:34.960 INFO (pid:84652) [attach] - receive notification: openLink []
2021-04-02T17:11:35.507 INFO (pid:84652) [attach] - receive notification: highlight []
2021-04-02T17:11:38.163 INFO (pid:84652) [attach] - receive notification: showInfo []

Describe the bug

I'm currently building a language server for a Markdown flavor and found a weird bug when implementing documentLink.

Given the following Markdown document containing a few links:

# Index

* [Note 1](note1.md)
* [Note 2](note2.md)
* [Note 3](note3.md)

When I try to open one linked document with CocAction('openLink'), the LSP communication with my server seems correct:

--> request #1: textDocument/documentLink: {"textDocument":{"uri":"file:///private/tmp/test/index.md"}}

<-- result #1: textDocument/documentLink: [
    {"range":{"start":{"line":2,"character":2},"end":{"line":2,"character":20}},"target":"file:///private/tmp/test/note1.md","tooltip":"Note 1"},
    {"range":{"start":{"line":3,"character":2},"end":{"line":3,"character":20}},"target":"file:///private/tmp/test/note2.md","tooltip":"Note 2"},
    {"range":{"start":{"line":4,"character":2},"end":{"line":4,"character":20}},"target":"file:///private/tmp/test/note3.md","tooltip":"Note 3"}
]

However, coc.nvim opens the wrong document:

• If the cursor is on [Note 1](note1.md), it will open note2.md.
• If it is anywhere else (even when not on a link), it will open note1.md.

When checking the links with :CocList links, they seem correct: [j]ump shows the proper range and [o]pen goes to the right document.

Test with documentLink/resolve

In a second attempt, I didn't set the target for the textDocument/documentLink request, to receive the documentLink/resolve and check the requested link. I noticed the same behavior:

• If the cursor is on [Note 1](note1.md), the range is the one of the note2.md link.
• If it is anywhere else (even when not on a link), the range is the one of the note1.md link.

--> request #1: textDocument/documentLink: {"textDocument":{"uri":"file:///private/tmp/test/index.md"}}
<-- result #1: textDocument/documentLink: [
    {"range":{"start":{"line":2,"character":2},"end":{"line":2,"character":20}},"tooltip":"Note 1"},
    {"range":{"start":{"line":3,"character":2},"end":{"line":3,"character":20}},"tooltip":"Note 2"},
    {"range":{"start":{"line":4,"character":2},"end":{"line":4,"character":20}},"tooltip":"Note 3"}
]

--> request #2: documentLink/resolve: {
    "range": {
        "start":{"line":3,"character":2},
        "end":{"line":3,"character":20}
    },
    "tooltip":"Note 2",
    "data":{"source":"71887081-200d-4c38-9a2a-03d46baded9b"}
}

Reproduce the bug

I can share the Language Server if needed to reproduce the issue. I could reproduce the problem with the following minimal vimrc:

call plug#begin('~/.vim/plugged')
Plug 'neoclide/coc.nvim', {'branch': 'release'}
call plug#end()

nmap <silent> <CR> <Plug>(coc-openlink)

I use this coc-settings.json to start my server:

{
  "languageserver": {
    "zk": {
      "command": "zk",
      "args": ["lsp"],
      "trace.server": "verbose",
      "filetypes": ["markdown"]
    }
  }
}

After opening a Markdown, I used my <CR> mapping to trigger openLink.

I could also reproduce the same problem with the official gopls language server, following these instructions, I have:

  "languageserver": {
    "golang": {
      "command": "gopls",
      "rootPatterns": ["go.mod", ".vim/", ".git/", ".hg/"],
      "filetypes": ["go"],
      "initializationOptions": {
        "usePlaceholders": true
      }
    }
  }

And with the following Go file:

package main

// http://google.com
// http://github.com

If I trigger openLink on http://google.com, it will open GitHub with my browser. But if I trigger it anywhere else, it opens Google.

Screenshots (optional)

I recorded two videos showing the problem:

• This one shows vim opening the wrong documents
• This one shows the wrong offset received with documentLink/resolve

[chemzqm]

Fixed on latest release branch of coc.nvim.

[mickael-menu]

@chemzqm It works great, thanks a lot for fixing this so quickly!